Such camera modules are used in vehicles to record the vehicle surroundings, in order to be able to use the image data for a variety of functions such as e.g. for lane detection, traffic sign recognition, high-beam assistance, collision warning, pedestrian detection, etc., wherein interventions in the vehicle control systems, e.g. brake or engine control systems, also take place on the basis of the evaluated image data. The quality of the same in terms of focusing and tilting is crucial for the use of such camera modules as a fixed-focus camera system in driver assistance systems.
These camera modules generally have a construction made up of a printed circuit board which serves as a support plate and which is equipped with an image sensor, and an optics module fixed thereon with an optics housing accommodating a lens.
In order to focus the optics module a fixture is required which makes it possible to adjust the distance between the lens of the optics module and the image sensor. In the simplest case, this is effected via a screw thread. The disadvantage of this is that adjustment is therefore only possible along an axis and, as a result, tilting and decentering of the lens with respect to the image sensor are not feasible and, as a consequence, not all image regions are in focus.
In order to be able to adjust multiple axes, an adhesive connection is frequently selected and the optics are, in the process, simultaneously aligned in multiple axes to the image sensor. However, the disadvantage of using adhesive beads is that the adhesive expands or contracts during the curing and drying of the adhesive and in the event of a temperature change and over its lifetime, resulting in a change in position of the lens relative to the image sensor, which leads to a blurry picture. In addition, the long drying times in the curing oven of approx. 30 to 60 minutes are also disadvantageous.
A generic camera module is known from DE 103 44 67 A1, which is incorporated by reference, which can be mounted without complex adjusting and focusing. This camera module comprises a circuit carrier, a housed image sensor arranged on the circuit carrier and an optics module comprising optics and an optics housing. A support is designed as a ring collar on the housing of the image sensor, on which support the optics module can support itself. It can be considered a disadvantage of this camera module that an image sensor with a specially embodied housing is required.